Background and aims: Early detection of hypotension benefits in deciding on preventative measures, safe anesthesia for the mother, and improved outcomes for the newborn. Reduced cardiac output from blood pooling in blocked body parts and decreased vascular resistance from sympathetic blockade cause hypotension after spinal anesthesia for Caesarean section. Peripheral perfusion dynamics resulting from variations in peripheral vascular tone have been evaluated using the perfusion index (PI) obtained from a pulse oximeter. This study aims to determine whether the baseline perfusion index can be used to predict hypotension following spinal anaesthesia in a caesarean section. Methods: In this prospective double blind observational study,140 patients were enrolled.PI and blood pressure, heart rate were monitored at baseline. every 3 minutes for the first fifteen minutes and then every 5 minutes until the end of the surgery, after administering spinal anaesthesia with 10mg hyperbaric bupivacaine. The incidence of hypotension was compared with baseline PI.ROC curve was plotted for PI and prediction of hypotension. Results: There was a significant association between baseline PI and hypotension. In our study, it was observed that the patients with baseline cut off of PI>3.8 the risk of hypotension was high in the first 10-12 minutes following spinal anaesthesia.The sensitivity and specificity for the 3.8 cut off of PI were 88.6% and 69.2% respectively. Conclusion: Our study found that a baseline PI cut off of 3.8 has higher predictability for hypotension risk within the first 10-12 minutes following spinal anaesthesia.